Consider what MeshAttachment needs for it to be rendered:
It needs verts, uvs, triangles, 1 material.
If you have a source for this information, you can insert it into the skeleton render.
Note the steps in SkeletonRenderer.cs
STEP 1 needs vertex counts and the material
STEP 2 needs the verts and uvs
STEP 3 needs the triangles
Each attachment type requires different handling for each of those steps in SkeletonRenderer and ArraysMeshGenerator.
Stuff like positioning, performance and shader compatibility will be a different matter.